我有一个工作的spring启动应用程序，包括单元测试。但是当我将amazonsimpleemailservice特性添加到项目中时，spring应用程序可以毫无问题地工作并发送电子邮件，但是单元测试正在运行 mvn clean install 引发异常：

Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.cloud.aws.core.region.StaticRegionProvider]: Constructor threw exception; nested exception is java.lang.IllegalArgumentException: The region '' is not a valid region!
Caused by: java.lang.IllegalArgumentException: The region '' is not a valid region!

请注意，我添加了aws-config.xml：

<beans xmlns="http://www.springframework.org/schema/beans"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:aws-context="http://www.springframework.org/schema/cloud/aws/context"
  xsi:schemaLocation="http://www.springframework.org/schema/beans
                       http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
                       http://www.springframework.org/schema/cloud/aws/context
                       http://www.springframework.org/schema/cloud/aws/context/spring-cloud-aws-context-1.0.xsd">

  <aws-context:context-credentials>
    <aws-context:simple-credentials access-key="${cloud.aws.credentials.accessKey:}" secret-key="${cloud.aws.credentials.secretKey:}"/>
  </aws-context:context-credentials>

  <aws-context:context-region region="${cloud.aws.region.static:}"/>
</beans>

以及application.yml文件中的配置：

cloud:
  aws:
    stack:
      auto: false
    region:
      static: us-west-2
      auto: false
    credentials:
      accessKey: __SomeAccessKey__
      secretKey: __SomeSecretKey__

有什么想法吗？